A system can provide non-expert designers an environment for building models (e.g. rules, classifiers, etc.) to perform Natural Language Understanding (NLU) processing. The system can build a project that includes a “concept ontology,” which describes the concepts that the NLU system needs to understand, such as “ticketing” or “directions.” These concepts are considered “intents,” which are the user's goal for the machine interaction. Typically, such a project is built by the user examining statistics of grammars and based on manual analysis, deciding which intents and mentions best fit the project.